solubility in alcohol, acquiring a very disagreeable odor, and the property of spotting clothes.

Those, on the contrary, obtained by distillation, are white, fluid, more or less sweet in odor, and very soluble in alcohol. They keep well and wet the clothes without spotting or greasing them.

Distilled essence of lemon.-Cut into small pieces a dozen of lemons, and put both juice and peels into a well-covered vessel, with 3 pints of lukewarm water; infuse until next day in a water-bath, then pour the whole in a still, lute, and distil with a good fire. The liquor that first runs over, is poured into a glass bottle to settle. As the essence is lighter than the water, it rises to the top, and is separable by reversing the bottle, the finger upon the mouth permitting its gradual emission through a partial opening. This inversion of the bottle changes the position of the liquids, and thus the water having escaped, the essence is retained by immediately closing the orifice.

Essence de Portugal. This essential oil of orange, known as above, is manufactured like the oil of petit grain, and is subject to similar adulteration. It is obtained in Portugal, from the orangettes (unripe oranges), by a process similar to those before mentioned. It is frequently adulterated with

alcohol, and this admixture is not easily to be detected. It has been proposed to agitate the oil with a little water, which occasions a milkiness if alcohol is present, whilst it remains clear if there is none; but this is unsatisfactory.

Distilled essence of oranges.-Slice a number of unripe oranges, and macerate them in a close vessel with warm water for a day or more, and then operate as for the distilled essence of lemon.

The detection of spirits of turpentine in other essences.-Peppermint and lavender, and all those oils whose native odor.is so strong that it is difficult to recognize the presence of a foreign admixture, are adulterated with such impunity, that some method of testing their purity has for a long time been necessary. Spirits of turpentine is almost

the exclusive diluent used for their falsification, and its property of easily dissolving grease, suggested to MERO the employment of fat to detect its presence in the essential oils.

Accordingly, he made mixtures in different proportions, and tried lard, almond oil, olive oil, oil of poppy, &c. After a number of experiments he ascertained with certainty the preference of the latter oil by reason of its uniform consistence without regard to temperature. It was the oil of

poppy, in fine, which gave the most exact results, and enabled the detection of spirits of turpentine,

even when mixed in small proportion with the essences before mentioned.

His process was as follows: he took 56 grains of oil of poppy, and placing it in a graduated glass tube, then added an equal quantity of the essence to be essayed. When the mixture is shaken up, it becomes milky-white if the essence is pure; whilst, if turpentine is present, it remains clear and transparent.

This process can be verified by first trying a pure essence, and then another adulterated with turpentine. If turpentine is present, even in small proportion, it will be seen that there is no change induced in the essence by the addition of oil, whereas if it is absent, under the same circumstances, the oil will be milky.

To make this trial successfully, it is necessary that the two essences be thoroughly blended. To Τα effect this, we give the method employed in commerce. Take of pure essence and add the requisite quantity of turpentine, pour them into a vessel, and heat over a water-bath until the mixture, at first slightly troubled, becomes completely transparent. In this way the mixture is exactly insured.

Adulteration of attar of rose.-Guibourt (Journ. de Pharm. 1849), after showing the unreliableness of the physical characters, as a test of purity, because of the readiness with which they may be imitated, proposes three tests for distinguishing the true attar. The usual adulterants are oils of rosewood and geranium. They may be detected as follows:

By iodine. The suspected attar is placed in watch-glasses, under a bell, along with a capsule containing iodine. The vapors of iodine, after some hours, condense, and form a brown areola upon the oil, if adulterated, but do not change its color, if pure. On exposure to air, the iodine volatilizes, but the color, in either case, remains unaltered.

By nitrous acid.-This serves only to detect the oil of geranium, to which it imparts an apple-green color; as it tinges the attar and oil of rosewood alike dark yellow.

By sulphuric acid.-This reagent turns all three of the oils brown, but the attar retains the purity of its odor, while that of the oil of rosewood is rendered more perceptible; the geranium oil, at the same time, acquiring a strong and unpleasant smell.

CHAPTER XLI.

OF SPIRITUOUS ODORS OR EXTRACTS.

THESE spirits are alcoholic extracts of the perfumes contained in pomades or fatty bodies.

1st process for extracting the perfume from greasy bodies.-Into each of three digesters or vessels, with well-fitting covers, and all heated by water-baths, put 25 lbs. of any perfumed antique oil, say oil à la rose, and pour on the first 25 quarts of spirit, and agitate and digest the whole for three days; at the end of this time decant the spirit thus perfumed, and pour it anew into the second vessel, and afterwards repeat the operation as at first upon the third quantity. This spirit thus obtained will be complete.

2d process. Select a deep and sufficiently large stoneware vessel, and in it melt by a water-bath 4 lbs. of double pomade from flowers, either jonquil, hyacinth, tuberose, or attar, and then add there to 4 quarts of perfectly inodorous alcohol. Cover the vessel well, and digest the whole for two weeks or a month, stirring frequently with a spatula.

The